Effect of Chemical Reagents on Physical and Mechanical Properties of Wood Flour-Polypropylene Composites

In this research, the effects of different chemical reagents on physical and mechanical properties of wood flour-polypropylene composites were investigated. For this purpose, wood flour and polypropylene were compounded (at 50% fiber loading) in a counter-rotating twin-screw extruder in the presence or absence of MAPP to produce the composites. The nominal cross section of the manufactured composites was 70*10 mm2. The specimens were immersed in NaOH (10%), HCl (10 %) and NaClO (2 %). After one week of immersion, the specimens were oven- dried and changes of oven-dried weight and mechanical properties (flexural modulus, flexural strength and un-notched impact strength) were determined. The mechanical properties of the composites immersed in chemical solutions were compared with the non-immersed composites (as control). From the results, the composites immersed in NaOH exhibited higher oven dried weight whereas those immersed in HCl and NaClO exhibited lower oven dried weights. All chemical reagents significantly reduced the mechanical properties of the composites. The addition of 2% MAPP could not considerably reduce the effect of chemical reagents on mechanical properties of studied formulations.